1 files changed, 212 insertions, 167 deletions

diff --git a/builtin/am.c b/builtin/am.c
index e4a0ff9..022cae2 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -3,14 +3,19 @@
  *
  * Based on git-am.sh by Junio C Hamano.
  */
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
-#include "cache.h"
-#include "config.h"
+#define USE_THE_INDEX_VARIABLE
 #include "builtin.h"
-#include "exec-cmd.h"
+#include "abspath.h"
+#include "advice.h"
+#include "config.h"
+#include "editor.h"
+#include "environment.h"
+#include "gettext.h"
+#include "hex.h"
 #include "parse-options.h"
 #include "dir.h"
 #include "run-command.h"
+#include "hook.h"
 #include "quote.h"
 #include "tempfile.h"
 #include "lockfile.h"
@@ -18,21 +23,23 @@
 #include "refs.h"
 #include "commit.h"
 #include "diff.h"
-#include "diffcore.h"
 #include "unpack-trees.h"
 #include "branch.h"
+#include "object-name.h"
+#include "preload-index.h"
 #include "sequencer.h"
 #include "revision.h"
 #include "merge-recursive.h"
 #include "log-tree.h"
 #include "notes-utils.h"
 #include "rerere.h"
-#include "prompt.h"
 #include "mailinfo.h"
 #include "apply.h"
 #include "string-list.h"
-#include "packfile.h"
+#include "pager.h"
+#include "path.h"
 #include "repository.h"
+#include "pretty.h"
 
 /**
  * Returns the length of the first line of msg.
@@ -81,9 +88,22 @@ enum signoff_type {
 	SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
 };
 
-enum show_patch_type {
-	SHOW_PATCH_RAW = 0,
-	SHOW_PATCH_DIFF = 1,
+enum resume_type {
+	RESUME_FALSE = 0,
+	RESUME_APPLY,
+	RESUME_RESOLVED,
+	RESUME_SKIP,
+	RESUME_ABORT,
+	RESUME_QUIT,
+	RESUME_SHOW_PATCH_RAW,
+	RESUME_SHOW_PATCH_DIFF,
+	RESUME_ALLOW_EMPTY,
+};
+
+enum empty_action {
+	STOP_ON_EMPTY_COMMIT = 0,  /* output errors and stop in the middle of an am session */
+	DROP_EMPTY_COMMIT,         /* skip with a notice message, unless "--quiet" has been passed */
+	KEEP_EMPTY_COMMIT,         /* keep recording as empty commits */
 };
 
 struct am_state {
@@ -109,6 +129,7 @@ struct am_state {
 
 	/* various operating modes and command line options */
 	int interactive;
+	int no_verify;
 	int threeway;
 	int quiet;
 	int signoff; /* enum signoff_type */
@@ -117,6 +138,7 @@ struct am_state {
 	int message_id;
 	int scissors; /* enum scissors_type */
 	int quoted_cr; /* enum quoted_cr_action */
+	int empty_type; /* enum empty_action */
 	struct strvec git_apply_opts;
 	const char *resolvemsg;
 	int committer_date_is_author_date;
@@ -177,6 +199,25 @@ static int am_option_parse_quoted_cr(const struct option *opt,
 	return 0;
 }
 
+static int am_option_parse_empty(const struct option *opt,
+				     const char *arg, int unset)
+{
+	int *opt_value = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
+	if (!strcmp(arg, "stop"))
+		*opt_value = STOP_ON_EMPTY_COMMIT;
+	else if (!strcmp(arg, "drop"))
+		*opt_value = DROP_EMPTY_COMMIT;
+	else if (!strcmp(arg, "keep"))
+		*opt_value = KEEP_EMPTY_COMMIT;
+	else
+		return error(_("invalid value for '%s': '%s'"), "--empty", arg);
+
+	return 0;
+}
+
 /**
  * Returns path relative to the am_state directory.
  */
@@ -444,10 +485,12 @@ static void am_destroy(const struct am_state *state)
  */
 static int run_applypatch_msg_hook(struct am_state *state)
 {
-	int ret;
+	int ret = 0;
 
 	assert(state->msg);
-	ret = run_hook_le(NULL, "applypatch-msg", am_path(state, "final-commit"), NULL);
+
+	if (!state->no_verify)
+		ret = run_hooks_l("applypatch-msg", am_path(state, "final-commit"), NULL);
 
 	if (!ret) {
 		FREE_AND_NULL(state->msg);
@@ -464,24 +507,12 @@ static int run_applypatch_msg_hook(struct am_state *state)
  */
 static int run_post_rewrite_hook(const struct am_state *state)
 {
-	struct child_process cp = CHILD_PROCESS_INIT;
-	const char *hook = find_hook("post-rewrite");
-	int ret;
-
-	if (!hook)
-		return 0;
-
-	strvec_push(&cp.args, hook);
-	strvec_push(&cp.args, "rebase");
-
-	cp.in = xopen(am_path(state, "rewritten"), O_RDONLY);
-	cp.stdout_to_stderr = 1;
-	cp.trace2_hook_name = "post-rewrite";
+	struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;
 
-	ret = run_command(&cp);
+	strvec_push(&opt.args, "rebase");
+	opt.path_to_stdin = am_path(state, "rewritten");
 
-	close(cp.in);
-	return ret;
+	return run_hooks_opt("post-rewrite", &opt);
 }
 
 /**
@@ -758,7 +789,7 @@ static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
  * A split_mail_conv() callback that converts an StGit patch to an RFC2822
  * message suitable for parsing with git-mailinfo.
  */
-static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr)
+static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
 {
 	struct strbuf sb = STRBUF_INIT;
 	int subject_printed = 0;
@@ -841,7 +872,7 @@ static int split_mail_stgit_series(struct am_state *state, const char **paths,
  * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
  * message suitable for parsing with git-mailinfo.
  */
-static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr)
+static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
 {
 	struct strbuf sb = STRBUF_INIT;
 	int rc = 0;
@@ -1047,7 +1078,7 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	else
 		write_state_text(state, "applying", "");
 
-	if (!get_oid("HEAD", &curr_head)) {
+	if (!repo_get_oid(the_repository, "HEAD", &curr_head)) {
 		write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
 		if (!state->rebasing)
 			update_ref("am", "ORIG_HEAD", &curr_head, NULL, 0,
@@ -1090,7 +1121,7 @@ static void am_next(struct am_state *state)
 	unlink(am_path(state, "original-commit"));
 	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 
-	if (!get_oid("HEAD", &head))
+	if (!repo_get_oid(the_repository, "HEAD", &head))
 		write_state_text(state, "abort-safety", oid_to_hex(&head));
 	else
 		write_state_text(state, "abort-safety", "");
@@ -1119,13 +1150,23 @@ static const char *msgnum(const struct am_state *state)
 static void NORETURN die_user_resolve(const struct am_state *state)
 {
 	if (state->resolvemsg) {
-		printf_ln("%s", state->resolvemsg);
+		advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", state->resolvemsg);
 	} else {
 		const char *cmdline = state->interactive ? "git am -i" : "git am";
+		struct strbuf sb = STRBUF_INIT;
+
+		strbuf_addf(&sb, _("When you have resolved this problem, run \"%s --continue\".\n"), cmdline);
+		strbuf_addf(&sb, _("If you prefer to skip this patch, run \"%s --skip\" instead.\n"), cmdline);
+
+		if (advice_enabled(ADVICE_AM_WORK_DIR) &&
+		    is_empty_or_missing_file(am_path(state, "patch")) &&
+		    !repo_index_has_changes(the_repository, NULL, NULL))
+			strbuf_addf(&sb, _("To record the empty patch as an empty commit, run \"%s --allow-empty\".\n"), cmdline);
 
-		printf_ln(_("When you have resolved this problem, run \"%s --continue\"."), cmdline);
-		printf_ln(_("If you prefer to skip this patch, run \"%s --skip\" instead."), cmdline);
-		printf_ln(_("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
+		strbuf_addf(&sb, _("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);
+
+		advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", sb.buf);
+		strbuf_release(&sb);
 	}
 
 	exit(128);
@@ -1247,14 +1288,9 @@ static int parse_mail(struct am_state *state, const char *mail)
 		goto finish;
 	}
 
-	if (is_empty_or_missing_file(am_path(state, "patch"))) {
-		printf_ln(_("Patch is empty."));
-		die_user_resolve(state);
-	}
-
 	strbuf_addstr(&msg, "\n\n");
 	strbuf_addbuf(&msg, &mi.log_message);
-	strbuf_stripspace(&msg, 0);
+	strbuf_stripspace(&msg, NULL);
 
 	assert(!state->author_name);
 	state->author_name = strbuf_detach(&author_name, NULL);
@@ -1309,7 +1345,8 @@ static void get_commit_info(struct am_state *state, struct commit *commit)
 	size_t ident_len;
 	struct ident_split id;
 
-	buffer = logmsg_reencode(commit, NULL, get_commit_output_encoding());
+	buffer = repo_logmsg_reencode(the_repository, commit, NULL,
+				      get_commit_output_encoding());
 
 	ident_line = find_commit_header(buffer, "author", &ident_len);
 	if (!ident_line)
@@ -1341,7 +1378,7 @@ static void get_commit_info(struct am_state *state, struct commit *commit)
 		die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
 	state->msg = xstrdup(msg + 2);
 	state->msg_len = strlen(state->msg);
-	unuse_commit_buffer(commit, buffer);
+	repo_unuse_commit_buffer(the_repository, commit, buffer);
 }
 
 /**
@@ -1368,6 +1405,7 @@ static void write_commit_patch(const struct am_state *state, struct commit *comm
 	add_pending_object(&rev_info, &commit->object, "");
 	diff_setup_done(&rev_info.diffopt);
 	log_tree_commit(&rev_info, commit);
+	release_revisions(&rev_info);
 }
 
 /**
@@ -1381,9 +1419,9 @@ static void write_index_patch(const struct am_state *state)
 	struct rev_info rev_info;
 	FILE *fp;
 
-	if (!get_oid("HEAD", &head)) {
+	if (!repo_get_oid(the_repository, "HEAD", &head)) {
 		struct commit *commit = lookup_commit_or_die(&head, "HEAD");
-		tree = get_commit_tree(commit);
+		tree = repo_get_commit_tree(the_repository, commit);
 	} else
 		tree = lookup_tree(the_repository,
 				   the_repository->hash_algo->empty_tree);
@@ -1399,7 +1437,8 @@ static void write_index_patch(const struct am_state *state)
 	rev_info.diffopt.close_file = 1;
 	add_pending_object(&rev_info, &tree->object, "");
 	diff_setup_done(&rev_info.diffopt);
-	run_diff_index(&rev_info, 1);
+	run_diff_index(&rev_info, DIFF_INDEX_CACHED);
+	release_revisions(&rev_info);
 }
 
 /**
@@ -1445,6 +1484,7 @@ static int run_apply(const struct am_state *state, const char *index_file)
 	int res, opts_left;
 	int force_apply = 0;
 	int options = 0;
+	const char **apply_argv;
 
 	if (init_apply_state(&apply_state, the_repository, NULL))
 		BUG("init_apply_state() failed");
@@ -1452,7 +1492,14 @@ static int run_apply(const struct am_state *state, const char *index_file)
 	strvec_push(&apply_opts, "apply");
 	strvec_pushv(&apply_opts, state->git_apply_opts.v);
 
-	opts_left = apply_parse_options(apply_opts.nr, apply_opts.v,
+	/*
+	 * Build a copy that apply_parse_options() can rearrange.
+	 * apply_opts.v keeps referencing the allocated strings for
+	 * strvec_clear() to release.
+	 */
+	DUP_ARRAY(apply_argv, apply_opts.v, apply_opts.nr);
+
+	opts_left = apply_parse_options(apply_opts.nr, apply_argv,
 					&apply_state, &force_apply, &options,
 					NULL);
 
@@ -1482,14 +1529,15 @@ static int run_apply(const struct am_state *state, const char *index_file)
 	strvec_clear(&apply_paths);
 	strvec_clear(&apply_opts);
 	clear_apply_state(&apply_state);
+	free(apply_argv);
 
 	if (res)
 		return res;
 
 	if (index_file) {
 		/* Reload index as apply_all_patches() will have modified it. */
-		discard_cache();
-		read_cache_from(index_file);
+		discard_index(&the_index);
+		read_index_from(&the_index, index_file, get_git_dir());
 	}
 
 	return 0;
@@ -1525,14 +1573,14 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
 	struct commit *result;
 	char *their_tree_name;
 
-	if (get_oid("HEAD", &our_tree) < 0)
+	if (repo_get_oid(the_repository, "HEAD", &our_tree) < 0)
 		oidcpy(&our_tree, the_hash_algo->empty_tree);
 
 	if (build_fake_ancestor(state, index_path))
 		return error("could not build fake ancestor");
 
-	discard_cache();
-	read_cache_from(index_path);
+	discard_index(&the_index);
+	read_index_from(&the_index, index_path, get_git_dir());
 
 	if (write_index_as_tree(&orig_tree, &the_index, index_path, 0, NULL))
 		return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
@@ -1552,7 +1600,8 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
 		rev_info.diffopt.filter |= diff_filter_bit('M');
 		add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
 		diff_setup_done(&rev_info.diffopt);
-		run_diff_index(&rev_info, 1);
+		run_diff_index(&rev_info, DIFF_INDEX_CACHED);
+		release_revisions(&rev_info);
 	}
 
 	if (run_apply(state, index_path))
@@ -1564,8 +1613,8 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
 
 	say(state, stdout, _("Falling back to patching base and 3-way merge..."));
 
-	discard_cache();
-	read_cache();
+	discard_index(&the_index);
+	repo_read_index(the_repository);
 
 	/*
 	 * This is not so wrong. Depending on which base we picked, orig_tree
@@ -1608,13 +1657,13 @@ static void do_commit(const struct am_state *state)
 	const char *reflog_msg, *author, *committer = NULL;
 	struct strbuf sb = STRBUF_INIT;
 
-	if (run_hook_le(NULL, "pre-applypatch", NULL))
+	if (!state->no_verify && run_hooks("pre-applypatch"))
 		exit(1);
 
-	if (write_cache_as_tree(&tree, 0, NULL))
+	if (write_index_as_tree(&tree, &the_index, get_index_file(), 0, NULL))
 		die(_("git write-tree failed to write a tree"));
 
-	if (!get_oid_commit("HEAD", &parent)) {
+	if (!repo_get_oid_commit(the_repository, "HEAD", &parent)) {
 		old_oid = &parent;
 		commit_list_insert(lookup_commit(the_repository, &parent),
 				   &parents);
@@ -1660,7 +1709,7 @@ static void do_commit(const struct am_state *state)
 		fclose(fp);
 	}
 
-	run_hook_le(NULL, "post-applypatch", NULL);
+	run_hooks("post-applypatch");
 
 	strbuf_release(&sb);
 }
@@ -1749,7 +1798,8 @@ static void am_run(struct am_state *state, int resume)
 
 	unlink(am_path(state, "dirtyindex"));
 
-	if (refresh_and_write_cache(REFRESH_QUIET, 0, 0) < 0)
+	if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
+					 NULL, NULL, NULL) < 0)
 		die(_("unable to write index file"));
 
 	if (repo_index_has_changes(the_repository, NULL, &sb)) {
@@ -1762,6 +1812,7 @@ static void am_run(struct am_state *state, int resume)
 	while (state->cur <= state->last) {
 		const char *mail = am_path(state, msgnum(state));
 		int apply_status;
+		int to_keep;
 
 		reset_ident_date();
 
@@ -1791,8 +1842,29 @@ static void am_run(struct am_state *state, int resume)
 		if (state->interactive && do_interactive(state))
 			goto next;
 
+		to_keep = 0;
+		if (is_empty_or_missing_file(am_path(state, "patch"))) {
+			switch (state->empty_type) {
+			case DROP_EMPTY_COMMIT:
+				say(state, stdout, _("Skipping: %.*s"), linelen(state->msg), state->msg);
+				goto next;
+				break;
+			case KEEP_EMPTY_COMMIT:
+				to_keep = 1;
+				say(state, stdout, _("Creating an empty commit: %.*s"),
+					linelen(state->msg), state->msg);
+				break;
+			case STOP_ON_EMPTY_COMMIT:
+				printf_ln(_("Patch is empty."));
+				die_user_resolve(state);
+				break;
+			}
+		}
+
 		if (run_applypatch_msg_hook(state))
 			exit(1);
+		if (to_keep)
+			goto commit;
 
 		say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
 
@@ -1826,6 +1898,7 @@ static void am_run(struct am_state *state, int resume)
 			die_user_resolve(state);
 		}
 
+commit:
 		do_commit(state);
 
 next:
@@ -1855,22 +1928,27 @@ next:
 /**
  * Resume the current am session after patch application failure. The user did
  * all the hard work, and we do not have to do any patch application. Just
- * trust and commit what the user has in the index and working tree.
+ * trust and commit what the user has in the index and working tree. If `allow_empty`
+ * is true, commit as an empty commit when index has not changed and lacking a patch.
  */
-static void am_resolve(struct am_state *state)
+static void am_resolve(struct am_state *state, int allow_empty)
 {
 	validate_resume_state(state);
 
 	say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);
 
 	if (!repo_index_has_changes(the_repository, NULL, NULL)) {
-		printf_ln(_("No changes - did you forget to use 'git add'?\n"
-			"If there is nothing left to stage, chances are that something else\n"
-			"already introduced the same changes; you might want to skip this patch."));
-		die_user_resolve(state);
+		if (allow_empty && is_empty_or_missing_file(am_path(state, "patch"))) {
+			printf_ln(_("No changes - recorded it as an empty commit."));
+		} else {
+			printf_ln(_("No changes - did you forget to use 'git add'?\n"
+				    "If there is nothing left to stage, chances are that something else\n"
+				    "already introduced the same changes; you might want to skip this patch."));
+			die_user_resolve(state);
+		}
 	}
 
-	if (unmerged_cache()) {
+	if (unmerged_index(&the_index)) {
 		printf_ln(_("You still have unmerged paths in your index.\n"
 			"You should 'git add' each file with resolved conflicts to mark them as such.\n"
 			"You might run `git rm` on a file to accept \"deleted by them\" for it."));
@@ -1907,9 +1985,9 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 	if (parse_tree(head) || parse_tree(remote))
 		return -1;
 
-	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
+	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 
-	refresh_cache(REFRESH_QUIET);
+	refresh_index(&the_index, REFRESH_QUIET, NULL, NULL, NULL);
 
 	memset(&opts, 0, sizeof(opts));
 	opts.head_idx = 1;
@@ -1917,10 +1995,11 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 	opts.dst_index = &the_index;
 	opts.update = 1;
 	opts.merge = 1;
-	opts.reset = reset;
+	opts.reset = reset ? UNPACK_RESET_PROTECT_UNTRACKED : 0;
+	opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
 	opts.fn = twoway_merge;
-	init_tree_desc(&t[0], head->buffer, head->size);
-	init_tree_desc(&t[1], remote->buffer, remote->size);
+	init_tree_desc(&t[0], &head->object.oid, head->buffer, head->size);
+	init_tree_desc(&t[1], &remote->object.oid, remote->buffer, remote->size);
 
 	if (unpack_trees(2, t, &opts)) {
 		rollback_lock_file(&lock_file);
@@ -1946,7 +2025,7 @@ static int merge_tree(struct tree *tree)
 	if (parse_tree(tree))
 		return -1;
 
-	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
+	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 
 	memset(&opts, 0, sizeof(opts));
 	opts.head_idx = 1;
@@ -1954,7 +2033,7 @@ static int merge_tree(struct tree *tree)
 	opts.dst_index = &the_index;
 	opts.merge = 1;
 	opts.fn = oneway_merge;
-	init_tree_desc(&t[0], tree->buffer, tree->size);
+	init_tree_desc(&t[0], &tree->object.oid, tree->buffer, tree->size);
 
 	if (unpack_trees(1, t, &opts)) {
 		rollback_lock_file(&lock_file);
@@ -1984,12 +2063,12 @@ static int clean_index(const struct object_id *head, const struct object_id *rem
 	if (!remote_tree)
 		return error(_("Could not parse object '%s'."), oid_to_hex(remote));
 
-	read_cache_unmerged();
+	repo_read_index_unmerged(the_repository);
 
 	if (fast_forward_to(head_tree, head_tree, 1))
 		return -1;
 
-	if (write_cache_as_tree(&index, 0, NULL))
+	if (write_index_as_tree(&index, &the_index, get_index_file(), 0, NULL))
 		return -1;
 
 	index_tree = parse_tree_indirect(&index);
@@ -2026,7 +2105,7 @@ static void am_skip(struct am_state *state)
 
 	am_rerere_clear();
 
-	if (get_oid("HEAD", &head))
+	if (repo_get_oid(the_repository, "HEAD", &head))
 		oidcpy(&head, the_hash_algo->empty_tree);
 
 	if (clean_index(&head, &head))
@@ -2068,7 +2147,7 @@ static int safe_to_abort(const struct am_state *state)
 		oidclr(&abort_safety);
 	strbuf_release(&sb);
 
-	if (get_oid("HEAD", &head))
+	if (repo_get_oid(the_repository, "HEAD", &head))
 		oidclr(&head);
 
 	if (oideq(&head, &abort_safety))
@@ -2101,7 +2180,7 @@ static void am_abort(struct am_state *state)
 	if (!has_curr_head)
 		oidcpy(&curr_head, the_hash_algo->empty_tree);
 
-	has_orig_head = !get_oid("ORIG_HEAD", &orig_head);
+	has_orig_head = !repo_get_oid(the_repository, "ORIG_HEAD", &orig_head);
 	if (!has_orig_head)
 		oidcpy(&orig_head, the_hash_algo->empty_tree);
 
@@ -2119,28 +2198,26 @@ static void am_abort(struct am_state *state)
 	am_destroy(state);
 }
 
-static int show_patch(struct am_state *state, enum show_patch_type sub_mode)
+static int show_patch(struct am_state *state, enum resume_type resume_mode)
 {
 	struct strbuf sb = STRBUF_INIT;
 	const char *patch_path;
 	int len;
 
 	if (!is_null_oid(&state->orig_commit)) {
-		const char *av[4] = { "show", NULL, "--", NULL };
-		char *new_oid_str;
-		int ret;
+		struct child_process cmd = CHILD_PROCESS_INIT;
 
-		av[1] = new_oid_str = xstrdup(oid_to_hex(&state->orig_commit));
-		ret = run_command_v_opt(av, RUN_GIT_CMD);
-		free(new_oid_str);
-		return ret;
+		strvec_pushl(&cmd.args, "show", oid_to_hex(&state->orig_commit),
+			     "--", NULL);
+		cmd.git_cmd = 1;
+		return run_command(&cmd);
 	}
 
-	switch (sub_mode) {
-	case SHOW_PATCH_RAW:
+	switch (resume_mode) {
+	case RESUME_SHOW_PATCH_RAW:
 		patch_path = am_path(state, msgnum(state));
 		break;
-	case SHOW_PATCH_DIFF:
+	case RESUME_SHOW_PATCH_DIFF:
 		patch_path = am_path(state, "patch");
 		break;
 	default:
@@ -2182,79 +2259,40 @@ static int parse_opt_patchformat(const struct option *opt, const char *arg, int
 	 * when you add new options
 	 */
 	else
-		return error(_("Invalid value for --patch-format: %s"), arg);
+		return error(_("invalid value for '%s': '%s'"),
+			     "--patch-format", arg);
 	return 0;
 }
 
-enum resume_type {
-	RESUME_FALSE = 0,
-	RESUME_APPLY,
-	RESUME_RESOLVED,
-	RESUME_SKIP,
-	RESUME_ABORT,
-	RESUME_QUIT,
-	RESUME_SHOW_PATCH
-};
-
-struct resume_mode {
-	enum resume_type mode;
-	enum show_patch_type sub_mode;
-};
-
 static int parse_opt_show_current_patch(const struct option *opt, const char *arg, int unset)
 {
 	int *opt_value = opt->value;
-	struct resume_mode *resume = container_of(opt_value, struct resume_mode, mode);
 
+	BUG_ON_OPT_NEG(unset);
+
+	if (!arg)
+		*opt_value = opt->defval;
+	else if (!strcmp(arg, "raw"))
+		*opt_value = RESUME_SHOW_PATCH_RAW;
+	else if (!strcmp(arg, "diff"))
+		*opt_value = RESUME_SHOW_PATCH_DIFF;
 	/*
 	 * Please update $__git_showcurrentpatch in git-completion.bash
 	 * when you add new options
 	 */
-	const char *valid_modes[] = {
-		[SHOW_PATCH_DIFF] = "diff",
-		[SHOW_PATCH_RAW] = "raw"
-	};
-	int new_value = SHOW_PATCH_RAW;
-
-	BUG_ON_OPT_NEG(unset);
-
-	if (arg) {
-		for (new_value = 0; new_value < ARRAY_SIZE(valid_modes); new_value++) {
-			if (!strcmp(arg, valid_modes[new_value]))
-				break;
-		}
-		if (new_value >= ARRAY_SIZE(valid_modes))
-			return error(_("Invalid value for --show-current-patch: %s"), arg);
-	}
-
-	if (resume->mode == RESUME_SHOW_PATCH && new_value != resume->sub_mode)
-		return error(_("--show-current-patch=%s is incompatible with "
-			       "--show-current-patch=%s"),
-			     arg, valid_modes[resume->sub_mode]);
-
-	resume->mode = RESUME_SHOW_PATCH;
-	resume->sub_mode = new_value;
+	else
+		return error(_("invalid value for '%s': '%s'"),
+			     "--show-current-patch", arg);
 	return 0;
 }
 
-static int git_am_config(const char *k, const char *v, void *cb)
-{
-	int status;
-
-	status = git_gpg_config(k, v, NULL);
-	if (status)
-		return status;
-
-	return git_default_config(k, v, NULL);
-}
-
 int cmd_am(int argc, const char **argv, const char *prefix)
 {
 	struct am_state state;
 	int binary = -1;
 	int keep_cr = -1;
 	int patch_format = PATCH_FORMAT_UNKNOWN;
-	struct resume_mode resume = { .mode = RESUME_FALSE };
+	enum resume_type resume_mode = RESUME_FALSE;
 	int in_progress;
 	int ret = 0;
 
@@ -2267,6 +2305,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOL('i', "interactive", &state.interactive,
 			N_("run interactively")),
+		OPT_BOOL('n', "no-verify", &state.no_verify,
+			N_("bypass pre-applypatch and applypatch-msg hooks")),
 		OPT_HIDDEN_BOOL('b', "binary", &binary,
 			N_("historical option -- no-op")),
 		OPT_BOOL('3', "3way", &state.threeway,
@@ -2283,12 +2323,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 			N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
 		OPT_BOOL('m', "message-id", &state.message_id,
 			N_("pass -m flag to git-mailinfo")),
-		OPT_SET_INT_F(0, "keep-cr", &keep_cr,
-			N_("pass --keep-cr flag to git-mailsplit for mbox format"),
-			1, PARSE_OPT_NONEG),
-		OPT_SET_INT_F(0, "no-keep-cr", &keep_cr,
-			N_("do not pass --keep-cr flag to git-mailsplit independent of am.keepcr"),
-			0, PARSE_OPT_NONEG),
+		OPT_SET_INT(0, "keep-cr", &keep_cr,
+			    N_("pass --keep-cr flag to git-mailsplit for mbox format"),
+			    1),
 		OPT_BOOL('c', "scissors", &state.scissors,
 			N_("strip everything before a scissors line")),
 		OPT_CALLBACK_F(0, "quoted-cr", &state.quoted_cr, N_("action"),
@@ -2326,26 +2363,29 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_NOARG),
 		OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
 			N_("override error message when patch failure occurs")),
-		OPT_CMDMODE(0, "continue", &resume.mode,
+		OPT_CMDMODE(0, "continue", &resume_mode,
 			N_("continue applying patches after resolving a conflict"),
 			RESUME_RESOLVED),
-		OPT_CMDMODE('r', "resolved", &resume.mode,
+		OPT_CMDMODE('r', "resolved", &resume_mode,
 			N_("synonyms for --continue"),
 			RESUME_RESOLVED),
-		OPT_CMDMODE(0, "skip", &resume.mode,
+		OPT_CMDMODE(0, "skip", &resume_mode,
 			N_("skip the current patch"),
 			RESUME_SKIP),
-		OPT_CMDMODE(0, "abort", &resume.mode,
+		OPT_CMDMODE(0, "abort", &resume_mode,
 			N_("restore the original branch and abort the patching operation"),
 			RESUME_ABORT),
-		OPT_CMDMODE(0, "quit", &resume.mode,
+		OPT_CMDMODE(0, "quit", &resume_mode,
 			N_("abort the patching operation but keep HEAD where it is"),
 			RESUME_QUIT),
-		{ OPTION_CALLBACK, 0, "show-current-patch", &resume.mode,
+		{ OPTION_CALLBACK, 0, "show-current-patch", &resume_mode,
 		  "(diff|raw)",
 		  N_("show the patch being applied"),
 		  PARSE_OPT_CMDMODE | PARSE_OPT_OPTARG | PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
-		  parse_opt_show_current_patch, RESUME_SHOW_PATCH },
+		  parse_opt_show_current_patch, RESUME_SHOW_PATCH_RAW },
+		OPT_CMDMODE(0, "allow-empty", &resume_mode,
+			N_("record the empty patch as an empty commit"),
+			RESUME_ALLOW_EMPTY),
 		OPT_BOOL(0, "committer-date-is-author-date",
 			&state.committer_date_is_author_date,
 			N_("lie about committer date")),
@@ -2355,6 +2395,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		{ OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
 		  N_("GPG-sign commits"),
 		  PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+		OPT_CALLBACK_F(0, "empty", &state.empty_type, "(stop|drop|keep)",
+		  N_("how to handle empty patches"),
+		  PARSE_OPT_NONEG, am_option_parse_empty),
 		OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
 			N_("(internal use for git-rebase)")),
 		OPT_END()
@@ -2363,7 +2406,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(usage, options);
 
-	git_config(git_am_config, NULL);
+	git_config(git_default_config, NULL);
 
 	am_state_init(&state);
 
@@ -2395,12 +2438,12 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		 *    intend to feed us a patch but wanted to continue
 		 *    unattended.
 		 */
-		if (argc || (resume.mode == RESUME_FALSE && !isatty(0)))
+		if (argc || (resume_mode == RESUME_FALSE && !isatty(0)))
 			die(_("previous rebase directory %s still exists but mbox given."),
 				state.dir);
 
-		if (resume.mode == RESUME_FALSE)
-			resume.mode = RESUME_APPLY;
+		if (resume_mode == RESUME_FALSE)
+			resume_mode = RESUME_APPLY;
 
 		if (state.signoff == SIGNOFF_EXPLICIT)
 			am_append_signoff(&state);
@@ -2414,7 +2457,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		 * stray directories.
 		 */
 		if (file_exists(state.dir) && !state.rebasing) {
-			if (resume.mode == RESUME_ABORT || resume.mode == RESUME_QUIT) {
+			if (resume_mode == RESUME_ABORT || resume_mode == RESUME_QUIT) {
 				am_destroy(&state);
 				am_state_release(&state);
 				return 0;
@@ -2425,7 +2468,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 				state.dir);
 		}
 
-		if (resume.mode)
+		if (resume_mode)
 			die(_("Resolve operation not in progress, we are not resuming."));
 
 		for (i = 0; i < argc; i++) {
@@ -2443,7 +2486,7 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		strvec_clear(&paths);
 	}
 
-	switch (resume.mode) {
+	switch (resume_mode) {
 	case RESUME_FALSE:
 		am_run(&state, 0);
 		break;
@@ -2451,7 +2494,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		am_run(&state, 1);
 		break;
 	case RESUME_RESOLVED:
-		am_resolve(&state);
+	case RESUME_ALLOW_EMPTY:
+		am_resolve(&state, resume_mode == RESUME_ALLOW_EMPTY ? 1 : 0);
 		break;
 	case RESUME_SKIP:
 		am_skip(&state);
@@ -2463,8 +2507,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 		am_rerere_clear();
 		am_destroy(&state);
 		break;
-	case RESUME_SHOW_PATCH:
-		ret = show_patch(&state, resume.sub_mode);
+	case RESUME_SHOW_PATCH_RAW:
+	case RESUME_SHOW_PATCH_DIFF:
+		ret = show_patch(&state, resume_mode);
 		break;
 	default:
 		BUG("invalid resume value");